1. Field of the Invention
The present invention relates to a liquid ejecting head for ejecting desired liquid using generation of a bubble by applying thermal energy to the liquid, a head cartridge using the liquid ejecting head, a liquid ejecting device using the same, a liquid ejecting method, and a recording method. It further relates to an ink jet head kit containing the liquid ejection head.
More particularly, it relates to a liquid ejecting head having a movable member displacable by generation of a bubble, and a head cartridge using the liquid ejecting head, and liquid ejecting device using the same. It further relates to a liquid ejecting method and recording method for ejection the liquid by moving the movable member using the generation of the bubble.
The present invention is applicable to equipment such as a printer, a copying machine, a facsimile machine having a communication system, a word processor having a printer portion or the like, and an industrial recording device combined with various processing device or processing devices, in which the recording is effected on a recording material such as paper, thread, fiber, textile, leather, metal, plastic resin material, glass, wood, ceramic and so on.
In this specification, "recording" means not only forming an image of letter, figure or the like having specific meanings, but also includes forming an image of a pattern not having a specific meaning.
2. Related Background Art
An ink jet recording method of so-called bubble jet type is known in which an instantaneous state change resulting in an instantaneous volume change (bubble generation) is caused by application of energy such as heat to the ink, so as to eject the ink through the ejection outlet by the force resulted from the state change by which the ink is ejected to and deposited on the recording material to form an image formation. As disclosed in U.S. Pat. No. 4,723,129, a recording device using the bubble jet recording method generally comprises an ejection outlet for ejecting the ink, an ink flow path in fluid communication with the ejection outlet, and an electrothermal transducer as energy generating means disposed in the ink flow path.
With such a recording method is advantageous in that, a high quality image, can be recorded at high speed and with low noise, and a plurality of such ejection outlets can be located at high density, and therefore, small size recording apparatus capable of providing a high resolution can be provided, and color images can be easily formed. Therefore, the bubble jet recording method is now widely used in printers, copying machines, facsimile machines or another office equipment, and for industrial systems such as textile printing device or the like.
With the increase of the wide needs for the bubble jet technique, various demands are imposed thereon, recently.
For example, an improvement in energy use efficiency is demanded. To meet the demand, the optimization of the heat generating element such as adjustment of the thickness of the protecting film is investigated. This method is effective in that a propagation efficiency of the generated heat to the liquid is improved.
In order to provide high image quality images, driving conditions have been proposed by which the ink ejection speed is increased, and/or the bubble generation is stabilized to accomplish better ink ejection. As another example, from the standpoint of increasing the recording speed, flow passage configuration improvements have been proposed by which the speed of liquid filling (refilling) into the liquid flow path is increased.
Among the configurations of the flow path Japanese Laid-Open Patent Application No. 63-199972 discloses an arrangement of the flow path as shown in FIGS. 1A and 1B. According to the arrangement of the flow path and a method for manufacturing a head as disclosed in the reference it hits on a back wave caused by generation of bubbles (the pressure in a direction opposite to a direction to the ejection outlet, namely to the liquid chamber 12). The back wave is know as an energy loss since the wave is not directed to the ejection direction.
The arrangement as shown in FIGS. 1A and 1B includes a valve 10 located at a position which is spaced apart from a bubble generation region formed by the heat generating element 2 and opposite to the ejection outlet 11 with respect to the heat generating element 2.
In FIG. 1B the valve 10 has an initial position as if it is adhered to a ceiling of a flow path 3 by a method using a plate-like material and the valve 10 depends down into the flow path 3 upon the generation of the bubble. According to the arrangement, a part of the back wave is controlled by the valve 10 so that the energy loss is controlled.
However, considering the generation of the bubble in the flow path 3 for keeping the liquid to be ejected, it is not practical to control the part of the back wave for the liquid ejection.
The back wave itself is not directly concerned with the ejection. When the back wave is generated in the flow path 3, the pressure of the bubble which is directly concerned with the ejection causes the liquid to be ejected from the flow path 3 as shown in FIG. 1A. Accordingly, even the back wave or the part thereof is controlled ejection outlet, the ejection is not greatly influenced.
On the other hand, in the bubble jet recording method, the heating is repeated with the heat generating element contacted with the ink, and therefore, a burnt material is deposited on the surface of the heat generating element due to kogation of the ink. However, the amount of the deposition may be large depending on the materials of the ink. If this occurs, the ink ejection becomes unstable. Additionally, even when the liquid to be ejected is the one easily deteriorated by heat or even when the liquid is the one with which the bubble generation is not sufficient, the liquid is desired to be ejected in good order without property change.
Japanese Laid-Open Patent Application No. 61-69467, Japanese Laid-Open Patent Application No. 55-81172 and U.S. Pat. No. 4,480,259 disclose that different liquids are used for the liquid generating the bubble by the heat (bubble generating liquid) and for the liquid to be ejected (ejection liquid). In these publications, the ink as the ejection liquid and the bubble generation liquid are completely separated by a flexible film of silicone rubber or the like so as to prevent direct contact of the ejection liquid to the heat generating element while propagating the pressure resulting from the bubble generation of the bubble generation liquid to the ejection liquid by the deformation of the flexible film. The prevention of the deposition of the material on the surface of the heat generating element and the increase of the selection latitude of the ejection liquid are accomplished, by such a structure.
However, with this structure in which the ejection liquid and the bubble generation liquid are completely separated, the pressure by the bubble generation is propagated to the ejection liquid through the expansion-contraction deformation of the flexible film, and therefore, the pressure is absorbed by the flexible film to a quite high degree. In addition, the deformation of the flexible film is not so large, and therefore, the energy use efficiency and the ejection force are deteriorated although the some effect is provided by the provision between the ejection liquid and the bubble generation liquid.